This invention is in the field of apparatus used to feed logs into the longitudinal centerline of apparatus such as debarkers. The invention relates to an improved method of mounting log engaging spikes on a log feeding roller. The invention also relates to an improved spike having upwardly inwardly inclined triangular faces to provide an improved grip on the logs engaged by the spikes of the roller.
Conventional log feeding rollers are of two types, rollers having exterior ribs to engage the logs and rollers having exterior spikes to engage the logs. Log feeding rollers must engage and advance a log at a continuous rate through the longitudinal centerline of a device acting on the log. The log feeding rollers are connected to hydraulic cylinders which exert pressure tangentially on the log feeding roller to maintain and advance the log along the longitudinal centerline of the device acting on the log. The ribs or spikes on the exterior of the log feeding roller form the actual contact between the log feeding roller and the log. This invention relates to spike rollers as opposed to rollers having exterior ribs for engaging logs.
In conventional spike feed rollers, conical spikes are welded to the exterior of the cylindrical surface of the feed rollers. The spikes are welded to the exterior of the cylindrical surface of the feed roller in close enough proximity to one another that the cylindrical surface of roller supporting adjacent spikes is subject to heat when adjacent spikes are welded on to the exterior surface of the feed rollers. The heat may weaken the weld holding adjacent spikes on the exterior surface of the feed roller.
When the exterior spikes on a feed roller are worn, the roller is removed. Individual spikes are physically removed from the cylindrical surface of the feed roller and new conical spikes are welded to the external surface of the feed roller. The removal or worn conical spikes and replacement with new conical spikes on a roller takes many hours depending in part on the diameter and length of the feeding roller. Large spike rollers require lift equipment to remove the spike roller.
The conical spikes commonly welded to feed rollers are made of conventional steel suitable for welding to the surface of the feed roller. Conical spikes generally in use are not made of alloy heat treated steel because of the problems associated with welding alloy heat treated metals to the cylindrical surface of the log feed roller.
When conical spikes are worn and the logs are frozen it may become necessary to increase the tangential pressure applied to the log feeding rollers to support and advance the logs at a continuous rate. Increase in the tangential pressure applied to log feeding rollers may in the long run cause wear to the log feeding roller, the housings and to the logs being fed by the log feeding or exiting roller.
It is an object of the invention to provide an improved spike roller for feeding logs in which the spikes may be mounted on the exterior of the cylindrical spike roller and removed and replaced on the surface of the spike roller more quickly than conventional conical spikes. The spikes of the instant invention may be changed without removing the roller from position.
It is another object of the invention to provide an improved spike roller in which the spikes are made from alloy steel with exterior surface hardening applied after machining providing longer wear and less down time in replacing spikes on the spike roller engaging incoming and exiting logs.
It is another object of the invention to provide a spike having a machined exterior surface with upwardly inwardly inclined triangular faces meeting at a point providing improved gripping of the exterior of incoming and outgoing logs thus limiting the tangential pressure which must be exerted by the log feeding rollers to maintain the logs on the longitudinal centerline and advance the logs at a constant rate through the debarker or other apparatus.
It is another object of the invention to provide a spike which will hold the log against torque exerted by debarkers or other devices without substantial increase of the tangential pressure applied to the log.
According to one aspect of the invention there is provided a roller for feeding or removing logs axially along the longitudinal axis of an apparatus, the roller comprised of a cylindrical surface and two side surfaces, the axis of the roller extending through the centers of the side surfaces of the feeding roller, the cylindrical surface having a series of spike bar retainers fastened across the cylindrical surface parallel to the central axis of the roller.
According to another aspect of the invention there is provided a roller for feeding or removing logs axially along the longitudinal axis of an apparatus, the roller comprised of a cylindrical surface and two side surfaces, the axis of the roller extending through the centers of the side surfaces of the feeding roller, the cylindrical surface having a series of spike bar retainers fastened circumferentially around the cylindrical surface.
According to another aspect of the invention there is provided a spike retaining bar for mounting on the cylindrical surface of a spike roller for feeding or removing logs axially along the longitudinal axis of an apparatus adapted to receive and retain a spike bar having a series of spaced vertical spikes on the cylindrical surface of the roller.
According to another aspect of the invention there is provided a bar including a series of spaced apart vertical spikes for mounting in s spike retaining bar fastened to the cylindrical surface of a roller for feeding or removing logs axially along the longitudinal axis of an apparatus.
According to another aspect of the invention there is provided a roller for feeding or removing logs axially along the longitudinal axis of an apparatus, the roller comprised of a cylindrical surface and two side surfaces, the axis of the roller extending through the centers of the side surfaces of the feeding roller, the cylindrical surface having a series of spike bar retainers fastened in a helical arrangement around the circumference of the cylinder. The spike bar retainers are normally located on one side of the helical arrangement of one roller and on the opposite side of the helical arrangement of a complementary roller.
According to another aspect of the invention the spike bars and the spike bar retainers of this invention may be mounted on rollers used to rotate logs as well as on rollers used to advance logs axially.